Senior Linux Systems Administrator – Secure DoD

Johns Hopkins Applied Physics Laboratory; Laurel (MD); On-site; USD 105,000 - 290,000; Full time

Benefits offered by this job

Education assistance

Robust retirement contributions

On-site facilities

Work-life balance

Job summary

Johns Hopkins Applied Physics Laboratory (APL) in Laurel, MD is seeking a Linux Systems Administrator to support secure, RMF-compliant environments in classified facilities. This role emphasizes implementation decisions, system improvements, and maintaining security posture across complex networks.

You will apply RMF/NIST controls, harden Linux platforms, and integrate Linux with Windows for hybrid workflows.

Qualifications

• Bachelor’s degree in Computer Science, Information Technology, or related field, or equivalent experience.
• 5+ years of professional experience as a Linux systems administrator in secure or complex environments.
• 1+ years of experience working with DoD Information Systems.
• Familiarity with Windows Active Directory, Linux Command line, Ansible, Samba, TCP/IP protocols, Storage Area Networks, Logical Volume Manager (LVM), NetApps, SLURM, virtualization.
• Are a strong teammate with a focus on exchanging information and collaboration.
• Are proficient in various operating systems, including Linux (RHEL7, RHEL8, RHEL9).
• Have knowledge of interoperability between Linux and Windows systems.
• Have experience administering systems in classified environments with RMF/NIST compliance.
• Excellent written and verbal communication skills with the ability to collaborate across engineering, program, and security teams.

Responsibilities

• Plan, build, validate, deploy, maintain, and upgrade computing and networking infrastructure. Specifically, via system administration of Linux-based systems, modern platforms, and grid servers.
• Recommend and implement changes that meet security protocols, the overall mission, and builds on the engineering team capabilities.
• Design, implement, and enforce system security hardening standards (STIG) in accordance with established compliance frameworks (RMF, NIST, etc.)
• Support installation and management of engineering, scientific, and analysis applications in secure, classified environments such as GitLab and MATLAB.
• Solve complex technical issues that impact system availability, performance, or security.
• Conduct routine system patching, upgrades, performance tuning, and security hardening.
• Integrate Linux systems with Windows platforms to support hybrid workflows in simulation environments.
• Manage a mixed operating system environment to validate new applications, configurations, and upgrades before deployment to production systems.
• Establish new user accounts and provide technical briefing to new users. Support facility and resident classified and unclassified IT needs. Manage user accounts, permissions, authentication services and system resources.
• Collaborate with engineers, cybersecurity staff, and program managers to ensure mission success.
• Develop and maintain operational documentation and standard operating procedures for assigned networks.
• Administer and troubleshoot network infrastructure to include switches, firewalls and type I network encryptors. Common technologies include Cisco, Aruba network switches, GD TACLANES, configuration of VLANS, port channels, routing and network security features.
• Work closely with the Information Assurance team to ensure compliance with DoD cybersecurity requirements. Determine necessary computer and software configurations for compliance with security requirements. Provide technical guidance on the mitigation of identified system vulnerability. Prepare for and support periodic security inspections.
• Build and configure new Linux systems and upgrade existing servers and workstations. Plan and execute software maintenance and upgrade tasks for servers, workstation and network software.
• Participate in the planning of facility, computer hardware, and software upgrades (including purchases) in order to support existing and emerging user needs. Work with users to gather system requirements.

Skills

Linux administration

RMF/NIST/compliance

DoD Information Systems

Windows interoperability

System hardening

Collaboration

Education

Bachelor’s degree in Computer Science, Information Technology, or related field

Master’s degree in Computer Science or IT

Tools

Ansible

SPLUNK

ACAS

PURIFILE

SLURM

GD TACLANES

Job description

Johns Hopkins Applied Physics Laboratory (APL) in Laurel, MD is seeking a Linux Systems Administrator to support secure, RMF-compliant environments in classified facilities. This role emphasizes implementation decisions, system improvements, and maintaining security posture across complex networks.

You will apply RMF/NIST controls, harden Linux platforms, and integrate Linux with Windows for hybrid workflows.